Rotary tiller



S. BURNS ROTARY TILLER Jan. 22, 1963 3 Sheets-Sheet 1 Filed April 26, 1961 FIG: 1

INVENI'OR $14M BURNS BY M 5677217266 ATTORNEY Jan. 22, 1963 s. BURNS 3,

ROTARY TILLER Filed April 26, 1961 5 Sheets-Sheet 2 |llllllllllllllllllllllllllllll! llllllllllllllllllllllllllllll'"v I 4,

INVENTOR 6 AM BUR/V5 BY M QMsm- SW ATTORNEY S. BURNS ROTARY TILLER Jan. 22, 1963 3 Sheets-Sheet 3 Filed April 26, 1961 INVENTOR mhw ATTORNEY United States Patent 3,074,490 ROTARY TILLER Sam Bums, Louisville, Ga. Filed Apr. 26, 1961, Ser. No. 105,790 5 Claims. (Cl. 172-42) The present invention relates to rotary tiller constructions and more especially to the improved means for effecting transmission of motive energy from a source of power to complemental cultivating and/ or carriage components and is a continuation-in-part of my copending application Serial No. 832,117, filed August 6, 1959 and now abandoned.

Conventional rotary tillers or walking cultivators comprise generally a frame assembly within which is mounted a drive or transmission housing and upon which are secured, at opposite ends, gasoline motor drive; hitch components; carriage components and means for guiding the instrument during operation. Rotary cultivating means are normally mounted adjacent the bottom of a transmission housing and transversely thereof, and connected thereby to the motor drive. Handle bars, including a pertinent motor drive control means for acceleration, engagement and disengagement, are pivoted upon the frame. Generally, the motor drive, hitch and drive housing components are bolted to the frame assembly resulting in lack of sufficient rigidity in the frame or chassis to support the various tiller components. Vibrations induced by operation of the motor drive and continuous irregular striking of the earth by the rotary tiller tines or slashers, result in loosening of the mounting bolts. Consequently, one experiences impaired efficiency and frequent breakdown of the components and means for transmitting power between respective motive and cultivating elements. This frame-type rotary tiller assembly, known in the art, is moreover lacking in rigidity due to interdependence upon a separate frame construction to effect means for interengaging the source of power to the operating instrument. Drive housings in the art are flimsy due to their thin-walled construction which is conventionally of light sheet metal. In such prior art devices, frame members within which the housing of the transmission is mounted abut the housing medially and support the housing against lateral bending which is induced by the moving action of the rotary tiller at the lower end of the housing. Yet, another shortcoming of such frame-type rotary tillers resides in top heaviness due to the pronounced extension of drive housing below the frame assembly and often above the same and where the extension of the housing is both below and above housing must be supported medially to prevent lateral bending.

In the present invention, this tiller construction includes a drive housing which is characterized by its rigidity and elongated triangular configuration which combinatively eliminates the necessity for a frame assernlby of the type currently known in the prior art. Additionally, the unique means for transmitting power from the engine components to the operating cultivators and reducing the speed thereof are unique by reason of the specific arrangement of gear reduction and transmission elements in the combination housing permitting both motor drive and hitch components to be attached directly to the motor drive or housing or transmission assembly. Additionally, due to the rigid construction of the drive housing bending moments applied thereto are reduced substantially completely. Moreover, since there is no requirement for medial support of the drive housing, the height of the housing may be reduced substantially resulting in consequent lower positioning of hitch and motor drive components and a lower center of gravity to the overall tilling instrument. Accordingly, the in- "ice ' stant rotary tiller is less top heavy than conventional tillers,

its length preferably exceeding its height, and therefore substantially more efficiently operated. The frame assembly, common to prior art devices is thus eliminated and the transmission may be substantially beneath the motor drive, resulting in a more compact, stabilized cultivating instrument. This invention also results in more facile access to the drive housing and reduced lateral bending and vibrational defects by reason of a lower center of gravity and unique positioning of motor drive.

Within the present invention, the tiller transmission includes a hardened steel gear and train transmission which is adapted to run friction-free due to the fact that the gear train elements operate in a bath of oil substantially heat free and needle bearings together with double seals bear the respective elements within the transmission to insure a longer and more efiicient operation. This gear case or transmission housing is preferably made of stamped steel, ground and hardened steel shafts journalled in needle bearings.

The objectives of invention include providing a sub-. stantially frameless assembly for a rotary tiller which is specifically adapted to maintain the operating components in a maximum utility and efiiciency correlation.

A further objective of invention resides in the creation of a rotary tiller wherein respective driving, tilling and control elements may be retained in rigid interconnection with means for transmitting motive power to the tilling 1 assembly.

A still further objective of invention is to create a rotary tiller construction in which the relative center of gravity is materially lower than in prior art devices, thereby creating increased efficiency of operation and control, during operation.

With the above and other objectsin view, which will become apparent as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein'disclosed may be made within the scope of what is claimed, without departing from the spirit of the invention.

In the accompanying drawings:

FIGURE 1 is a view in perspective of invention;

FIGURE 2 is a vertical sectional view of the housing shown in FIGURE 1, the specific section line being taken along the line 22 of FIGURE 3;

FIGURE 3 is an end sectional view of the transmission housing shown in FIGURE 2;

FIGURE 4 is a top plan view of the components shown in FIGURES 2 and 3 together with engine and hitch mounting elements;

FIGURE 5 is a side elevational view of the components shown in FIGURE 4. I

The basic tiller shown in FIGURE 1 comprises an engine having crank shaft and pulley 112, tension clutch, V-belt and sheave 114, 116 and 118 respectively, disposed in power transfer and idle relation to the gear transmission which is located beneath. The clutch is mounted for arcuate movement to engage and disengage the belt in the well known manner. The handle bars for the device are generally indicated by the numeral 120, the same engaging respectively engine and hitch mounts and having suitable clutch control. Cultivating depth control, during operation, is effected by the vertically adjustable brake having rearwardly inclined, ground-engaging prong 134, acting in complement to rotating and cultivating tines 140, the carriage wheels 136 being also suitably and adjustably located in the hitch for either additional depth control or carriage of the device during non-operating transport. The respective brake and carriage standard have adjusting bores 132 and 138 respec- 3 tively. permitting vertical adjustment as shown more specifically in FIGURE 5.. It will beobvious to those skilled in the art that various substitute static cultivating instruments may be used in lieu of the braking element 130'. For instance, it is within the spirit of invention to substitute combined ridging andhilling plows; double mold board plows; sweep plows either individually orin combination; plural pronged sidewishbone attachments in place or any combination of the aforementioned. Utilizing such attachments, the carriage assembly 136 is preferably removed. from the hitch.

With reference'now. to FIGURES 2 and 3', the transmission comprises opposed fiat-sided matched sections 153 and 150 the same defining a stamped cavity for the transmission elements. The uppermost portion of the gear train is retained in a small upright extension 152 of the housing. The configuration of the transmission gear case and its cavity extend from front to rear at 154 and 154 respectively, to provide a substantially symmetrical triangular shape. The trianglezwith its apexdownward has a base formed by the horizontal fore and aft top surface and has anever-diminishing, triangular configured lower portion expanded as at 156 and 156 to meet and form the lower cavity at 158, the lower cavity confining the drive sprocket. The entire gear and chain transmission is sealed in a bath of oil, by joining the respective opposed flanges 169 of the opposed matched sections 150 and 15%. a

Now the engine drive shaft 170being keyed to sheave 118 bears in the respective casing components 150 and 15% at 168 and 168' respectively in a needle bearing journal, the drive shaft being. keyed to driving gear 174,

which in turn has, meshing connection with idler spur gear 174'. Spur gear 174- rotates upon the idler axle 172, the latter having needle bearing support within the opposed easing depression counterparts 166 and 166'. It will be noted that the respective driving and spur gears 174 and 174' are each spacially set'within the housing by respectivespacer bushings 176 and 176.

The chain drive used in this system includes preferably a silent chain 186 in which together with the sprocket wheels one obtains rotational speed inversely proportional to the number of teeth. The. respective spur gears being equivalent in diameter are preferably attached to their corresponding shafts by Woodruff keyor the like, each being mounted for rotational interconnection with the reduction, gear 178, likewise bearing mounted substantially centrally of'the transmission housing in opposed casing depression counterparts 1'64 and 164. Now 'reduction gear 178 and sprocket 180'are each fixed together to transmit power through the chain/to the cultivator drive sprocket 13-2, saidsprocket being keyed to the driven cultivator shaft 184 mountedin opposed casing depression counterparts162 and162'. A suitable bushing 188 is utilized in connection with shaft 184 to prevent trans-- verse sliding movement.

In FIGURES 4 and 5 the static mount 250 and hitch 260 are each depicted. The mount 250 has'corresponding plane surfaces 252 and 252 upon which to mount the engine. Suitable flange 254 is adapted to engage the 4 casing flanges 160. Projections 256 and 256' inhibit excessive V-belt flapping during idling.

The hitch 260 is secured to flange 160- by a substantially angular element consisting of horizontal plates 262 and 262 and 264, terminating in a yoke having parallel arms 265, 265 which are spaced apart by the stabilizer 268. Adjustable retention of the standard and carriage stern 136 is efiected by bolts 266 per the FIGURES iliustration.

I claim:

1. A rotary tiller comprising a flat sided narrow transmission housing of substantially symmetrical triangular configuration disposed to extend in a fore and aft direction with its base uppermost and horizontal,

a short upright extension on said housing base positioned centrally of said housing in vertical relation to the apex thereof and forming an integral part of said housing,

a transverse drive shaft journalled in said housing extension,

at least one intermediate transverse shaft journalled in said housing,

a transverse driven shaft journalled in the apex of said housing,

gearing within said housing and housing extension interconnecting said drive shaft, intermediate shaft and said driven shaft,

said drive shaft, intermediate shaft and driven shaft lying in a vertical plane transverse to saidv housing,

a motor driving unit operatively connected to said drive shaft,

means on the base of said housing forwardly of said.

housing extension providing a support for said motor driving unit to which the same is secured,

rotary tiller means mounted on said driven shaft on each side of said housing,

and ground engaging control means, adjustably secured.

to the base of said housing rearwardly of said housing extension.

2. The rotary tiller of claim 1, wherein a bracket pro-. viding spaced parallel arms substantially in horizontal alignment with said motor driving'unit support extends rearwardly from the base of said housing, said control device including a standard fitted between said bracket arms, means adjustably securing said standard to said bracket arms, and a handle structure secured in part to said bracket. V f

3. The rotary tiller of claim 1 wherein the length of the housing exceeds its height.

4. The rotary tiller ofclaim 2 wherein the length of the housing exceeds its height.

5. The rotary tiller of claim 3 wherein the transmission further comprises opposed, matched sections which are sealed together.

References Cited in the file of'this patent UNITED STATES PATENTS 2,614,474 Merry Oct. 21, 1952 

1. A ROTARY TILLER COMPRISING A FLAT SIDED NARROW TRANSMISSION HOUSING OF SUBSTANTIALLY SYMMETRICAL TRIANGULAR CONFIGURATION DISPOSED TO EXTEND IN A FORE AND AFT DIRECTION WITH ITS BASE UPPERMOST AND HORIZONTAL, A SHORT UPRIGHT EXTENSION ON SAID HOUSING BASE POSITIONED CENTRALLY OF SAID HOUSING IN VERTICAL RELATION TO THE APEX THEREOF AND FORMING AN INTEGRAL PART OF SAID HOUSING, A TRANSVERSE DRIVE SHAFT JOURNALLED IN SAID HOUSING EXTENSION, AT LEAST ONE INTERMEDIATE TRANSVERSE SHAFT JOURNALLED IN SAID HOUSING, A TRANSVERSE DRIVEN SHAFT JOURNALLED IN THE APEX OF SAID HOUSING, GEARING WITHIN SAID HOUSING AND HOUSING EXTENSION INTERCONNECTING SAID DRIVE SHAFT, INTERMEDIATE SHAFT AND SAID DRIVEN SHAFT, SAID DRIVE SHAFT, INTERMEDIATE SHAFT AND DRIVEN SHAFT LYING IN A VERTICAL PLANE TRANSVERSE TO SAID HOUSING, A MOTOR DRIVING UNIT OPERATIVELY CONNECTED TO SAID DRIVE SHAFT, MEANS ON THE BASE OF SAID HOUSING FORWARDLY OF SAID HOUSING EXTENSION PROVIDING A SUPPORT FOR SAID MOTOR DRIVING UNIT TO WHICH THE SAME IS SECURED, ROTARY TILLER MEANS MOUNTED ON SAID DRIVEN SHAFT ON EACH SIDE OF SAID HOUSING, AND GROUND ENGAGING CONTROL MEANS, ADJUSTABLY SECURED TO THE BASE OF SAID HOUSING REARWARDLY OF SAID HOUSING EXTENSION. 